Advanced Stop Lines (ASLs)

Advanced Stop Lines (ASLs, or ‘cycle boxes’) are some of the cheapest, most cost-effective and popular ways to give cyclists visible priority at junctions. They help cyclists control their own safety as they prepare to manoeuvre through the junction, giving them the opportunity to position themselves where they can be clearly seen by drivers behind.

Key facts:

Around 75% of road crashes involving cyclists happen at or near junctions.

CTC View (formal statement of CTC's policy):

There should be a presumption in favour of providing Advanced Stop Lines (ASLs) on all arms of all signalised junctions.

Highway authorities should progressively introduce ASLs at all signalised junctions, making site-specific alterations to the junction layout as required. Exceptions may be made on high speed roads (40mph or above) where there are existing off-carriageway facilities that meet cyclists’ needs, or where a decision is taken to provide these.

The Government should pursue moves to clarify and amend the legislation covering cyclists’ access to and use of ASLs; and make civil enforcement of ASLs possible.

Each location needs to be carefully assessed to determine the most appropriate site-specific layout, having regard for the line of approach taken by cyclists and their turning movements. The safety benefits of different ASL layouts should be kept under review.

ASLs should be provided with at least one feeder lane on any junction arm where the traffic volumes and speeds merit the provision of a cycle lane (or cycle use of a bus lane), in accordance with CTC’s campaigns briefing on on-road cycling (forthcoming).

On any junction arm with more than one entry lane, consideration should be given to providing a feeder lane away from the kerb (i.e. either between or to the right of the general traffic lanes). This may be either in addition to or instead of a feeder lane to the left of the general traffic lanes. The safety benefits of different ASL layouts should be kept under review.

Feeder lanes should be at least 1.5m wide, preferably 2m, especially where cycle flows are high. General traffic lanes on junction approaches can be reduced to 2.5m to accommodate this, and 2.25m is acceptable on quieter streets with little or no bus or lorry traffic.

CTC recommends the progressive introduction of coloured surfacing for ASLs and their feeder lanes. Priority should be given to locations with multiple general traffic lanes and/or complex conflicting movements between cyclists and motorised traffic.